I have error code 077-304 on my machine. The error code is described as Tray 5 Top Cover Open. The cover is closed, but error still remains. I have been through the RAP and everything checked out. When I did the IOT check on 077-304 the display did not change. I then checked the circuit on the Tray 5 Top Cover Interlock and tried another tray, but nothing has worked so far. Anyone have any suggestions on what to do next or what to try. I have had two technicians from different companies out and neither of them could fix it. Please help.